OpenTTD is an open source simulation game based upon the popular Microprose game “Transport Tycoon Deluxe”, written by Chris Sawyer. It attempts to mimic the original game as closely as possible while extending it with new features.

OpenTTD is a business simulation game in which players try to earn money via transporting passengers and freight by road, rail, water and air. It is an open source remake and expansion of the 1995 Chris Sawyer video game Transport Tycoon Deluxe.

OpenTTD gameplay is very similar to Transport Tycoon Deluxe, on which it is based, although there are many improvements in both options within the game and ease of use. A player’s aim is to build a transportation network using trucks, busses, trains, airplanes and boats to link together industries and towns on the map and transport the cargo they produce. Every time a vehicle makes a delivery of some cargo, players receive an income, allowing them to build more infrastructure (rails, stations, etc.), build more vehicles, modify the terrain, and interact with towns, via their local authorities. The default game runs from 1950 to 2050, during which a player aims to get as high a performance rating (based on number of vehicles, income, amount of cargo delivered, etc.) as possible.

The world map is dotted with both industries and towns. Cargo for transportation is supplied by both industries (e.g. the coal mine which produces coal) and towns (which produce passengers and mail) and accepted by other industries and/or towns according to their needs (e.g., the power station accepts coal). Placing a station near a source and a receiver of a certain cargo allows transportation between the two. The amount of cargo supplied by a town or industry depends on the quality of transport players provide to move its goods. Payment for delivering cargo depends on the quantity of cargo delivered, how fast it was delivered and how perishable it is. Some cargoes (e.g., passengers) must be delivered faster than others (e.g., coal) to earn a good income.

OpenTTD is modelled after the original Transport Tycoon game by Chris Sawyer and enhances the game experience dramatically. Many features were inspired by TTDPatch while others are original.

Significant enhancements in OpenTTD from the original game include:

bigger maps (up to 64 times in size)

stable multiplayer mode for up to 255 players in 15 companies, or as spectators

dedicated server mode and an in-game console for administration

IPv6 and IPv4 support for all communication of the client and server

in game downloading of AIs, NewGRFs, scenarios and heightmaps

new pathfinding algorithms that makes vehicles go where you want them to

autorail/-road build tool, improved terraforming

canals, shiplifts, aqueducts

larger, non-uniform stations and the ability to join them together

mammoth and multi-headed trains

different configurable models for acceleration of vehicles

clone, autoreplace and autoupdate vehicles

the possibility to build on slopes and coasts

advanced/conditional orders, share and copy orders

longer and higher bridges including several new designs, plus fully flexible tracks/roads under bridges

reworked airport system with many more airports/heliports (e.g. international and metropolitan)

presignals, semaphores, path based signalling

support for TTDPatch NewGRF features offering many options for graphics and behaviour configuration/modification